Double screw cap and process of forming same



y 3 M. A. GREENE 2,001,248

DOUBLE SCREW CAP AND PROCESS OF FORMING SAME Original Filed July '7, 1932 gagu ml 3 a LL J a u 6 I Patented May 14, 1935 PATENT OFFICE DOUBLE SCREW CAP AND PROCESS OF I FORLHNG SAME Michael A. Greene, Wheeling; W. Va., assignor to Hazel-Atlas Glass 00., Wheeling, W. Va., a corporation of West Virginia Application July 7, 1932, Serial No. 621,263

- Renewed October 8, 1934 3 Claims.

The present invention relates to screw closures for bottles and jars and has for its primary object to provide a. double metallic cap having a plain exterior and a threaded interior, and in which 5 novel means is provided for obtaining a more secure connection between the inner and outer shells. I

One of the main obstacles in themanufacture of double caps resides in permanently and rigidly,

1 connecting the two shell sections in such manner that the connection will not interfere with the operation of the threads. .This obstacle is overcome in the present construction in which the lower edges of the inner and outer shells are permanently crimped together in a position entirely outside of the threaded zone.

A further object of the invention consists in providing a liquid proof joint or seam between the inner and outer shells so as to facilitate dipping 20 in various kinds of baths or solutions in finishing and plating operations. 4

A still further object of the invention resides in the provision of a double shell screw cap having a permanent and rigid connection between 5 the parts, but in which the main body of the cap will have an external diameter substantially the same as the external diameter of the mouth of the jar.

Another object of the invention-consists in a 30 novel process of preparing and assembling the inner and outer shells which compose the completed article.

Other objects and advantages of the invention will be apparent from the following description 35 when taken in connection with the accompanying drawing; in which,

inwardly to provide a bead extending partly' 50 around the bead on the inner shell; and

Figure 5 is an elevational view, partly in section, showing the-two sections permanently and rigidly united by compressing the concentrically,

arranged beads on the inner and outer shells:

55 The inner shell, which is indicated by the nu- Figure 1 is a vertical sectional view of the meral I, comprises a crown portion 2 and a skirt 3. This inner shell is substantially identical with that shown and described in the copending application of John J. Williams, Ser. No. 617,839, filed June 17, 1932, for Screw cap closures. As 5 stated in this earlier application, the skirt 3 is flared outwardly at its lower edge so that its connection with the outer shell will not interfere with the process of threading the closure onto a jar or the like. Screw threads 4 are formed on the-skirt 3, and the lower edge of the skirt is finished by a bead 5.

The outer shell is indicated bythe numeral 6 and comprises a crown portion 1 and a skirt 8. This shell is first formed into a blank as shownin Figure 1 as distinguished from the ordinary hatshaped blank usually formed as the first step in the production of metal caps. The skirt of the outer blank, according to the present invention, is provided with an 'oifset portion 9 from which depends asupplemental skirt portion l0 adapted to be formed into a bead as will presently appear. The ofiset portion 9 is of a width such that the supplemental skirt I0 is spaced laterally a substantial distance from the main skirt 8, and by reason of this offset position of the part III the latter may be bent inwardly to firmly grip the bead of the inner shell without in anyway interfering with the proper functioning of the threads '4.

By reference to Figure 3 it will be noted that the inner diameter of the main skirt 8 is the same as the outer diameter of the inner shell, except for the necessary clearance, and that the inner diameter of the supplemental skirt III is the same as the diameter of the bead 5, except for the necessary clearance. This is a material departure from prior double shell caps, for in theprior caps the skirt of the outer shell was of one diameter throughout, and obviously .such diameter was that of the bead. Thus the present construction not only constitutes a substantial saving in material, but also produces a cap in which the external diameter of the body of the cap is substantially less than has been possible heretofore in caps of this type, so that it will not be out of proportion to the size of the bottle or jar upon which it is mounted.

After the inner and outer'shells I and 6 are nested together as indicated in Figure 3, the sup- 0 plemental skirt I0 is turnediinwardly to form a I head H which encircles and is concentric with the bead 5 formed on the lower edge of the inner shell I. The cap as thus far'pconstructed is shown in Figure 4. The next and final step in the process of forming the structural features of the double cap consists in placing the article of Figure 4 in a machine to apply pressure to the upper and lower walls of the bead ll so asto collapse it and the inner bead 5 to the positions shown in Figure 5. This crimping of the beads 5 and I I causes a very rigid and permanent connection between the, inner and outer shells. This joint or seam between the shells is also highly advantageous in that it is liquid proof and thus permits the completed caps to be clipped in various kinds or solutions or baths for finishing and plating operations. t

From the above description and the attached drawing it will be apparent to those skilled in the art that I have devised a novel process of assembling the sections of a double screw cap; that the inner and outer sections of the cap are rigidly and permanently connected by a liquid-proof joint; that the joint is offset laterally of the main body of the cap so as to be beyond the zone of activity of the threaded interior of the cap; and that the major portion of the cap is of a diameter not substantially greater than the external diameter of the mouth of the container to which the cap is to be applied.

No claim is made to the broad idea of uniting an inner threaded shell and an outer smooth shell, as that was disclosed to the public many years ago, in the patent to Bernardin No. 653,610, July 10, 1900. And considered broadly it is inimaterial whether or not the inner shell of Bernardin is provided with a bead at the edge of the skirt,as such beads were old long prior to Bernardin. The present invention does not relate to such subject-matter, but to a construction and method in which the inner shell has a lower flaring portion provided with a bead, the two shells being of substantially the same diameter throughout their upper portion, and the lower portion of the outer shell being oflset at the bead and turned inwardly and upwardly substantially completely about the bead on the inner shell, which is made possible by the flaring portion on "the inner shell.

In accordance with the patent statutes I have described what I now believe to be the preferred form of the invention, but it will be understood that various changes may be made without departing from the spirit of the invention, and all such changes are intended to be included within the scope of the appended claims.

What I claim is: I

1. The process of forming a double screw cap which consists in forming a threaded inner shell with an outwardly flaredportion terminating in a bead, forming aplain outer shell with an offset portion and a depending flange, nesting the inner and outer shells, curling the depending flange inwardly to form a bead encircling said first-mentioned bead, and collapsing said beads.

2. A screw closure for bottles and jars, including an inner shell having a. top and a threaded skirt, an outwardly flared portion on the inner shell below the threads, a bead formed at the edge of the outwardly flared portion, a smooth outer shell within which the threaded shell is nested, the inner diameter of the outer shell being substantially the same as the outer diameter of the inner shell, an offset portion projecting laterally outward from the outer shell and turned inwardly and upwardly substantially completely about the bead on the inner shell, whereby the two shells are firmly united.

3. A screw closure for bottles and jars, including an inner shell having a top and a threaded skirt, an outwardly flared portion on the inner shell below the threads, a bead-formed at the edge of the outwardly flared portion, a smooth outer shell within which the threaded shell is nested, the inner diameter of the outer shell being substantially the same as the outer diameter of the inner shell, an offset portion projecting laterally outward from the outer shell and turned inwardly and upwardly substantially completely about the bead on the inner shell, the bead and the portion of the outer shell encircling the bead being flattened, for'the purpose described.

- MICHAEL A. GREENE. 

